Enhanced Privacy ID (EPID) is a technique for attestation of a trusted system while preserving privacy of the signer. EPID is an enhancement of the Direct Anonymous Attestation (DAA) algorithm. DAA is a digital signature algorithm that support anonymity of the signing entities. DAA provides a common group public key that is associated with the group of private signature keys. Devices may use a private signature key to sign a message, which may then be verified using the group public verification key. The recipient is unable to determine which of the devices signed the message. EPID provides additional functionality over DAA.